Water works

Cranfield University is to work with a number of major water companies and the government to develop technologies aimed at reducing energy use in water and wastewater treatment.

The EPSRC funded project is to establish a network in October promoting collaboration on research into the use of sustainable energy.

Partners include Thames, Severn Trent, Yorkshire, Northumbrian, and Anglian water companies, as well as United Utilities and government organisations such as the Environment Agency.

Universities with expertise in water or wastewater treatment processes or in energy conservation and renewable energy, such as Imperial College, Strathclyde, Birmingham, Warwick and Edinburgh, will also be involved.

The network is to be led by Dr Elise Cartmell of Cranfield University’s School of Applied Sciences, an expert in wastewater and groundwater treatment, sludge digestion, biogas optimisation and energy recovery from sludge. It will have a dedicated website and will hold meetings in the UK to promote a sharing of ideas regarding energy use.

Energy issues

Adopting new technologies will also help the water industry to cut operational costs in the face of increasing demand for water and rising energy costs. There is currently concern that some of the new technologies which are becoming standard are more energy intensive than conventional processes.

‘We will be looking at sustainability and energy issues within water treatment and waste management,’ said Cartmell. ‘This will include both lowering energy use and the optimisation of current processes. The network’s aim is to develop collaborative research proposals in this area.’

Cranfield already has strong links with water research groups in Europe, including Germany, Denmark and France, and has established new links with the Commonwealth Scientific and Research Organisation (CSIRO) in Australia and Awwa Research Forum in the US.

Technologies to be examined by the network include enhancing gas production for Combined Heat and Power (CHP) renewable power generation, biogas quality improvements, biogas clean up, and alternative renewable power generation such as using electricity from fuel cells, photovoltaics, biomass and hydroelectric sources, as well as blending energy resources.

On the wastewater side, it is thought that research will concern optimisation of standby generation, management of wastewater pumping networks, heat recovery opportunities, using biofuels and anaerobic processes, and the employment of bioengineering approaches for energy resource recovery.

Mains water used for everything from drinking to washing and flushing the toilet needs to be cleaned and treated for both safety and to protect the environment. However, the process uses around 8,000 GWh of electricity each year — equivalent to running about 100 million tumble driers non-stop over the same period. This figure is increasing by around two per cent each year. While water treatment standards are becoming more stringent, companies are increasing their demands for energy.

The coal, oil and gas used to generate this energy release carbon dioxide into the atmosphere, which contributes to global warming.

Climate Change Levy

By reducing the amount of energy that is used to treat drinking water, a significant difference could be made to the country’s emissions, reducing the impact on the environment and so the contribution to global warming.

The water industry’s use of fossil fuel energy is also taxed under the government’s Climate Change Levy, designed to reduce energy use, promote energy efficiency and encourage greater adoption of renewable sources. This costs the water industry over £15m annually, money which could be better used to improve the infrastructure. Furthermore, there are concerns that international pressure over climate change will cause energy use taxation to rise, meaning a move towards increasing sustainable energy generation is vital.

Water companies have already been attempting to reduce their energy costs and increase the sustainability of their operations by adopting more energy efficient practices such as upgrading equipment and improving system control measures and systems analysis to identify areas where energy consumption is high.

The Cranfield researchers will be looking at projects that include developing new treatment processes that use less energy, and increasing the use of alternative fuels through processes such as the production of biogas. This is produced during wastewater treatment and can be used as an alternative power source. However, renewable energy accounts for only just over six per cent of present energy use, despite the fact that energy accounts for around 28 per cent of the cost of treating waste water.